Temporary mechanical circulatory support for severe cardiac failure: experimental study

We describe a technique for mechanical cardiac assistance in an acute model of severe cardiac failure. Cardiac dysfunction was induced by a high dose of halothane in 13 dogs. Seven served as controls. Following median sternotomy, a pneumatically driven device was implanted in the other six dogs in a para-aortic position, using a simple surgical technique without cardiopulmonary bypass. The aorta was cross-clamped during cardiac assistance. During hemodynamic studies, the seven control animals with induced cardiac failure showed high end-diastolic left ventricular and right atrial pressures with low cardiac index and systolic left ventricular and aortic pressures. All dogs in this group died within 30 minutes. Use of a monovalvular cardiac assist device in the experimental group of six dogs to pump blood from the aortic root to the descending aorta in a counterpulsation manner, confirmed good preservation of systemic hemodynamic parameters after induction of heart failure. All animals in this treated group survived more than 45 minutes. Hemodynamically, the device acts as a new ventricle and the impaired left ventricle functionally becomes a left atrium. This condition is clinically appropriate for recovery of left ventricular function in severe acute myocardial failure.

Valve extension with glutaraldehyde-preserved autologous pericardium. Results in mitral valve repair

Preliminary experimental studies in our laboratory have shown that autologous pericardium treated with glutaraldehyde prevents late deterioration and calcification of the tissue. For this reason, glutaraldehyde-treated autologous pericardium has been used in a series of 64 patients who underwent operations for leaflet extension of the mitral valve between 1980 and 1989. Ages ranged from 2.5 to 60 years (mean 19 +/- 15). The causes of mitral valve insufficiency were rheumatic fever (69%), bacterial endocarditis (17%), congenital (8%), endomyocardial fibrosis (4.5%), and trauma (1.5%). The autologous tissue was fixed in a 0.62% glutaraldehyde solution for 15 minutes and rinsed in saline for an additional 15 minutes. Patching techniques varied depending on the site and the extent of the lesion. Associated mitral valve repair techniques (Carpentier's techniques) were mandatory in all patients. The period of follow-up extended from 6 months to 9 years (mean 3.1 +/- 2.5 years). There were no operative deaths in this series, and there was one late death (2%). In the six patients (12%) who underwent reoperation, there has been no case of calcification of the pericardial patch. Postoperative mitral valve function was assessed by bidimensional color Doppler echocardiographic techniques. Mitral valve insufficiency was trivial or absent in 80% of the patients. This experience permits us to conclude that leaflet extension is a simple and safe technique in valve reconstruction, allowing repair of mitral valves that otherwise would need to be replaced. It permits use of an adult-size prosthetic ring in children. Glutaraldehyde-treated autologous pericardium is the material of choice for this type of repair.

Mycotic aneurysms of the carotid arteries--case report and review of the literature

Mycotic aneurysms of the extracranial carotid arteries are rare. We report a new case with a mycotic aneurysm of the carotid bifurcation associated with acute bacterial endocarditis of the aortic valve. A concomitant treatment of both lesions was performed. Twenty-six cases of mycotic aneurysms of the extracranial carotid arteries have been reported in the literature. We present a review of all these cases.

Mitral valve repair in the extensively calcified mitral valve annulus

Mitral valve replacement in patients with an extensively calcified mitral annulus is associated with an increased risk of ventricular rupture. Until now techniques of mitral valve repair have not been applied to patients with a heavily calcified mitral valve annulus. We present 12 patients who underwent extensive decalcification of the annulus with subsequent mitral valve repair between 1987 and 1990. Ages ranged from 11 to 78 years; 6 patients were in New York Heart Association functional class II, 4 were in class III, and 2 were in class IV. All patients had varying degrees of mitral insufficiency. There were no deaths, reoperations, or thromboembolic events. Postoperative echocardiography revealed minimal residual mitral insufficiency in only 2 of 12 patients. All patients are currently in New York Heart Association class I or II. We believe mitral valve repair can be done safely on patients with an extensively calcified mitral annulus, thus avoiding the risks of left ventricular rupture, thromboembolic events, and hemorrhagic complications associated with mitral valve replacement.

[Demonstration of abnormalities of myocardial mitochondrial oxygenation in cardiac graft rejection]

Abnormalities of myocardial metabolism during acute rejection may be due to ischemia to primary metabolic changes related to rejection. An experimental study of heterotopic cardiac transplantation in the rat was undertaken to study myocardial mitochondrial oxidation during acute rejection. The receivers were Lewis rats and the donors Fischer (FL: allograft) or Lewis (LL: isograft) rats. The oxygen consumption of the mitochondria (VO2m) isolated from the transplanted and native hearts was measured by oxygraphy six days after transplantation. Using maleate and glutamate substrates, the VO2m of transplanted hearts was significantly lower than that of native hearts in the two groups of rats (FL, p less than 0.01; LL, p less than 0.01). In addition, the VO2m of FL allograft transplanted hearts was significantly lower than in the LL rats (30 +/- 9 vs 100 +/- 15 nanoatoms of oxygen/min.mg/prot, p less than 0.01) as was the VO2m of the native hearts (FL: 106 +/- 23 vs LL: 164 +/- 26, p less than 0.02). The respiratory control ratio (RCR) was significantly lower in the transplanted than in the native hearts in both the FL and LL groups (p less than 0.05 and p less than 0.01 respectively). The comparison of the RCR in the two groups (FL vs LL) showed no significant difference for transplanted or native hearts. Electron microscopy of transplanted (rejected or not) and native hearts showed no morphological abnormality of the mitochondria. The lower VO2m of the allograft group indicates a disturbance in the mitochondrial respiratory pathway during acute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Patient management and clinical follow-up after cardiomyoplasty

The purpose of this article is to provide an overview of patient management following latissimus dorsi cardiomyoplasty, based on clinical experience with 34 patients operated on between 1985 and 1990. Postoperative patient care includes: (1) clinical follow-up, (2) electrostimulation management, and (3) management of complications. The efficacy of cardiomyoplasty is principally evaluated by the quality-of-life before and after cardiomyoplasty (New York Heart Association [NYHA] functional class), number of rehospitalizations due to congestive heart failure, amount of pharmacological support, exercise capacity, postoperative reintegration and adaptation to working life, and late survival.

[Ascending aortic ectasia. New reinforcement technique]

Enlargement of the ascending aorta associated with dystrophic aortic incompetence frequently progresses to aneurysm and its complications. This potential course can be prevented by using a simple technique including insertion of a Mersuture net covering the entire ascending aorta, associated with local application of gelatin-resorcin-formalin glue.

Atrial cardiomyoplasty after Fontan-type procedures

The purpose of right atrial cardiomyoplasty is to increase atrial-pulmonary flow in patients undergoing Fontan-type procedures. We developed two surgical techniques to bypass the right ventricle, followed by right atrial cardiomyoplasty with a stimulated latissimus dorsi muscle flap (LDMF). In 10 goats, the left LDMF was transferred into the chest by removal of the second rib. After sternotomy, the right atrial appendages of five goats (group 1) were connected to the distal main pulmonary artery with polytetrafluoroethylene tubing and the proximal pulmonary trunks were ligated. In the other five goats (group 2), under cardiopulmonary bypass, bioprosthetic valves were implanted into the inferior venae cavae. The tricuspid orifice was closed, and the atriopulmonary connection was performed. The left LDMF was sutured over the right atrium and stimulated using synchronous 30-Hz bursts of impulses delivered by a Medtronic Cardiomyostimulator. Hemodynamic studies were performed in the acute phase. Right atrial, pulmonary arterial, and aortic pressures were assessed. Cardiac output was measured using ultrasonic flow studies. LDMF stimulation restored pulsatile pressure patterns in the pulmonary artery and increased the cardiac output. These observations were more evident in the model with caval valvular implant. This functional "ventricularization" of the right atrium could improve long-term results after Fontan-type procedures and extend operative indications. Chronic experimental studies are necessary to evaluate the diastolic and systolic functions of the neo-right ventricle.

Absorbable rings for pediatric valvuloplasty. Preliminary study

Secondary valvular stenosis is a significant risk of annular ring implantation during valvular repair in children. To avoid this problem, we have developed an absorbable prosthetic ring (APR), which induces the generation of a biologic fibroelastic ring with mitotic capability and thereby allows atrioventricular annulus growth with age. Twelve polydioxanone (PDS) biodegradable APRs were surgically implanted in immature goats. To avoid possible embolic complications from ring fragments during the absorption period, APRs were covered with an extensible sewing sheath of high-porosity polyester, allowing contact between the PDS, blood, and endocardium. Four APRs were implanted into the right atrial cavity, four in the tricuspid position, and four in the mitral position. Histological studies at 6 months showed a considerable amount of remaining PDS. At 1 year, only small residual fragments of PDS were present, surrounded by collagen and elastic fibers as well as fibroblasts with mitotic activity. This histological structure represents a new biologic fibroelastic ring, which has originated from PDS rings. Echocardiography at 12 months showed that the elasticity of APRs and fibrotic tissue allows normal systolic and diastolic valve motions. These findings, which demonstrate histological changes in native valve annuli as well as stable and elastic annuloplasty without secondary stenosis in growing animals, call for new studies involving hearts with valvular disease.

[Combined coronary and lower limb revascularization: a new technique]

The management of patients with concomitant coronary and aorto-iliac atherosclerosis is subject to controversy, but it is universally agreed that coronary artery surgery should precede aorto-iliac reconstruction. The technique described here consists of an ascending aorta to bifemoral graft. It allows combined surgery of the coronary and lower limb arteries to be performed without opening the peritoneum.

Kinking of the pulmonary artery: a treatable cause of acute right ventricular failure after heart transplantation

Kinking of the pulmonary artery has been reported only once as a cause of acute right ventricular failure after heart transplantation. We report two cases of kinking of the pulmonary artery encountered during a 3-year period (120 heart transplants). An analysis of the causes of this complication and a diagnostic and therapeutic approach are presented.

[Dynamic cardiomyoplasty. Hemodynamic study of 3 patients]

Dynamic cardiomyoplasty is a surgical operation aimed at compensating for a loss of substance or a severe deficiency of the left ventricular myocardium by implanting around the heart the latissimus dorsi muscle the contraction of which, synchronous with that of the ventricles, acts on the heart in the manner of a massage or milking. The operation, which in its present form is recent, consists of applying Onto the heart, or wrapping that organ with, a skeletal muscle that keeps its neurovascular supply and its high insertion, and of installing the appropriate electrodes and a pacemaker. We report the haemodynamic data collected in 3 patients operated upon for severe cardiac failure 13, 8 and 9 months ago respectively and who are now in NYHA functional stages I and II. During 1/1 stimulation of the latissimus dorsi systolic pressures remain unchanged while diastolic pressures rise; cardiac output increases satisfactorily in two of the patients (cases No. 1 and 3) and is unmodified in the third one (case No. 2). We conclude that cardiomyoplasty seems to give favourable results but its future and indications remain to be determined.

[Benign tumors of the heart (excluding myxoma). Experience with 9 surgically treated cases]

Benign non myxomatous cardiac tumors are rare. Between 1968 and 1988, 9 patients presenting benign non myxomatous cardiac tumors were operated in our institution. Tumors were: 2 rhabdomyomas, 2 lipomas, 2 fibromas, 1 pheochromocytomas, 1 mesothelioma and 1 papillary fibroelastoma. Total excision was possible in all cases but one (multiple fibromas). We hereby present a review of the literature on the subject. We focalize on the new imagery techniques in order to help the diagnosis and on the new surgical possibilities (cardiomyoplasty) which make possible complete surgical excision.

Biatrial transseptal approach in case of difficult exposure to the mitral valve

The biatrial transseptal approach according to the Dubost technique provides an excellent exposure to the mitral valve. Over a 5-year period (1984 to 1989) we used this approach in 210 patients. We believe that this incision is indicated in the following situations: reoperation on the mitral valve and acute mitral insufficiency with little enlargement of the left atrium.